Applying two joint frailty models for assessing Survival and Recurrence rate in patients with Head and Neck cancer

The objective of the present study was to compare performance of two joint frailty models and to assess survival and recurrence rate of HNC and their associated risk factors.This retrospective cohort study was conducted on 179 HNC patients from April 2007 to November 2013 in Tehran, Iran. Two outcomes were simultaneously analysed: time betweendiagnosis and disease recurrence or inter-recurrences; time between diagnosis and death. Two joint frailty models were utilized to data analysis andLikelihood cross-validation (LCVa) was used to compare them. From 179 patients, 52.5% experienced relapse at least one time and 15.6% of cases deceased. The survival rate in 12-, 24-, and 60- month were 94.4%, 83.1%, and 55.4%, respectively. The mean±SD of survival time was 49.80±3.37 months which was longer in patients with relapse (52.20 versus 28.30). Although, deceased patientswere more in relapse group than non-relapse, but the mean of survival time in them was longer. Advanced stage and the age older than 50 significantly increased the risk of death.Thus, early detection can prevent the premature death.The value of LCVa in general joint frailty model was less than joint frailty model.So, General joint frailty model has better performance in this study.